1. Field of the Invention
The present invention pertains to welding helmets for protecting the face and sides of a welder's head from being struck by molten metal, sparks, ultra violet and other radiation and other debris generated when a welding operation is taking place. Normally, the helmet features a front piece with a light filtering window so that the welder can watch the welding process while at the same time his eyes are protected from the intense light, including ultra violet and infra red radiaion, generated especially in an arc-welding operation. The front piece is generally a continuation of two rearwardly extending sides which serve to partially encircle the welder's head to protect the sides of the head from flying debris.
2. Description of the Prior Art
Except for the flexible ear portion covers, U.S. Pat. No. 3,327,318 discloses a conventional welder's helmet or mask as they are sometimes called. The conventional helmet includes a head piece or cradle which fits over the welder's head and supports the helmet (mask) in relation to the welder's head. Normally, the helmet is held in a spaced relationship to the welder's head so that air can circulate between the helmet and the welder's head to prevent excessive perspiration and discomfort due to heat.
Since there are adverse physiological conditions associated with most welding operations, considerable effort has been devoted to improving the welder's environment. The two major adverse physiological conditions are excessive noise and air pollution. In regard to the latter condition, U.S. Pat. Nos. 2,354,502 and 3,535,707 demonstrate attempts to modify existing welding helmets to provide means to control air pollution or otherwise upgrade the atmospheric conditions surrounding the welder's head.
As noted above, one attempt at reducing noise pollution or the adverse effects of noise is demonstrated by U.S. Pat. No. 3,327,318, which discloses means for accommodating sound attenuating ear muffs worn by the welder at the same time a welding helmet is worn in position for welding. Conventionally, noise abatement has followed the path of using ear muffs or sound attenuating ear cups which firmly engage the sides of the head while covering the ears.
In addition to the aforementioned patent, this method of noise abatement is disclosed in U.S. Pat. No. 3,621,488 in regard to a crash helmet. The major efforts in this type of sound attenuation have occurred in regard to crash hemlets, and in particular, to crash helmets or helmets worn by military air craft personnel. Examples of such devices are shown in U.S. Pat. Nos. 2,619,639; 2,802,214; 2,867,813; and 3,005,203.
It is well-known that the sound attenuating ear muffs are effective and are used widely in industry. However, the largest drawback of the sound attenuating ear muff is that it firmly grips the head of the wearer. Over long periods of time, e.g. an eight hour work shift, these ear muffs can create severe wearer discomfort from the physical pressure and from closing off air circulation thus promoting perspiration in and around the ears of the wearer.